JSON to QueryString

parse.js

const prefixes = (prev, next) => prev ? `${prev}[${next}]` : next

const serialize = (key, value, prefix = '') => {
  switch(value.constructor.name) {
    case "Array": return value.map((obj, i) => serialize(i+ "", obj, prefixes(prefix, key))).join('&')
    case "Object": return parse(value, prefixes(prefix, key))
    default: return prefixes(prefix, key) + '=' + value
  }
}

const parse = (json, prefix = '') =>
  Object.keys(json)
        .map(key => serialize(key, json[key], prefix))
        .join('&')

console.log(parse(
{
  "searchCriteria": {
    "pageSize": 10,
    "filterGroups": [
      {
        "filters": [
          {
            "field": "price",
            "value": 200,
            "condition_type": "lt"
          }
        ]
      },
      {
        "filters": [
          {
            "field": "sku",
            "value": "%red%",
            "condition_type": "like"
          }
        ]
      }
    ]
  }
}
))